import { Injectable, signal, computed } from '@angular/core';

const USER_ID_KEY = 'scn_user_id';
const ADMIN_KEY_KEY = 'scn_admin_key';

@Injectable({
  providedIn: 'root'
})
export class AuthService {
  private userId = signal<string | null>(null);
  private adminKey = signal<string | null>(null);

  isAuthenticated = computed(() => !!this.userId() && !!this.adminKey());

  constructor() {
    this.loadFromStorage();
  }

  private loadFromStorage(): void {
    const userId = localStorage.getItem(USER_ID_KEY);
    const adminKey = localStorage.getItem(ADMIN_KEY_KEY);
    if (userId && adminKey) {
      this.userId.set(userId);
      this.adminKey.set(adminKey);
    }
  }

  login(userId: string, adminKey: string): void {
    localStorage.setItem(USER_ID_KEY, userId);
    localStorage.setItem(ADMIN_KEY_KEY, adminKey);
    this.userId.set(userId);
    this.adminKey.set(adminKey);
  }

  logout(): void {
    localStorage.removeItem(USER_ID_KEY);
    localStorage.removeItem(ADMIN_KEY_KEY);
    this.userId.set(null);
    this.adminKey.set(null);
  }

  getUserId(): string | null {
    return this.userId();
  }

  getAdminKey(): string | null {
    return this.adminKey();
  }

  getAuthHeader(): string | null {
    const key = this.adminKey();
    return key ? `SCN ${key}` : null;
  }
}